Generic valve devices are readily available on the market in a plurality of embodiments, for example, as multiport valves. In conjunction with an electromagnetic actuation, they are an important component of the proportional valve technology. This technology is essentially characterized in that an electrical input signal as voltage is converted into an electrical current with an electronic amplifier of the corresponding voltage level.
A proportional solenoid as an switching magnet generates the output quantities force or path proportionally to this electrical current. These quantities are used as the input signal for the valve device or the hydraulic valve and, proportionally thereto, signify a specific volumetric flow or a specific pressure. For the respective actuated load and for a working element that has been actuated with it on a machine, in addition to influencing the direction of movement, this arrangement leads to the possibility of continuously influencing the speed and force. At the same time, according to a corresponding time characteristic, for example, change of the volumetric flow over time, acceleration or deceleration can be continuously influenced. Depending on the function being emphasized, that is, the path function, the flow function, and/or the pressure function, proportional hydraulics are used in directional valves, flow control valves, or so-called pressure valves.
The technical advantages of proportional valve technology include controlled actuation transitions, continuous control of the setpoints, and the reduction of the hydraulic apparatus for certain control tasks. Furthermore, with proportional valves, prompt and exact sequences of motion are possible with simultaneously improved accuracy of the control processes.
In practice, the known valve device solutions also leave much to be desired in the field of proportional valve technology for many control tasks, as can arise in double-acting hydraulic working cylinders in which the triggering takes place for positioning tasks while avoiding mechanical coupling elements, especially with respect to the operational reliability of the overall system as well as prompt reaction.
DE 43 19 162 A1 discloses a generic valve device with two opposing solenoids connected to a valve housing, with fluid connection sites mounted in the valve housing in the form of at least one pump connection P, at least two user connections A, B, and at least two tank connections T1 and T2. A valve piston has radial projections that can each be assigned to one fluid connection site A, B, T1, T2 at a time in the valve housing and fluid-conducting paths between the projections. In a neutral position block, the path to the respective assignable user connection A, B is blocked or cleared in part or in full. With the cleared user connections A, B cleared, the respective pressure connection P is completely blocked by the assignable projection. The known solution relates to a hydraulic valve that can be used for actuating a hydraulic actuator in a roll stabilization system of a motor vehicle.
DE 600 16 510 T2 describes a piloted directional valve with position determination. A housing has a number of connections and a housing bore in which each connection discharges. A valve piston is movably guided to be able to move axially in the bore to change the flow paths between the connections. Complex controls control the valve piston, with the controls comprising a piston on each side of the valve piston and one or two pilot valves for setting the valve piston by controlling the pilot fluid acting on the piston. A magnet is attached to one side of the valve piston such that it can be moved in synchronous operation with the valve piston. The magnet is arranged such that it borders at least one side of the valve piston. By a magnetic sensor, the magnetic force of the magnet can be detected over the entire displacement path of the valve piston.
DE 102 24 739 A1 discloses a valve device in which a first pilot chamber pressurizes a first back side of the valve piston and a second pilot chamber pressurizes a second piston back side. The pressure in the pilot chambers can be controlled by a first and second pilot pistons that can be moved by a first and a second electromagnet, respectively.